The Ohse Grant Foundation funded this work.

1. Cell Extension Characteristics
<ol>
	<li>Maintain SW-13, SW-Neo, and SW-DKK3 cells in a standard humidified incubator at 37.0 &#176;C and 5% CO2 in Dulbecco&#39;s Modified Eagle Medium supplemented with 10% fetal bovine serum and 10,000 U/mL penicillin and streptomycin (designated as &#39;growth medium&#39;).
	<ol>
		<li>Count cells using a hemocytometer, and plate 5,000 cells per well for SW-13, SW-Neo, and SW-DKK3 lines into separate 6-well plates and grow overnight in growth medium on sterile glass coverslips.</li>
	</ol>
	</li>
	<li>After overnight growth, for each well, aspirate the growth medium, wash cells with 1 mL of warm phosphate-buffered saline (PBS), and then fix the cells with 1 mL of 3.7% formaldehyde for 10 min.</li>
	<li>Aspirate formaldehyde and stain cells in each well with 1 mL of 0.05% crystal violet for 30 min. Wash excess dye away using three washes of 1 mL deionized water. 
	NOTE: Depending on the level of dye uptake, several additional washes may be needed to remove background staining to promote cell visualization.
	<ol>
		<li>Using fine tipped forceps, retrieve coverslips and place them face down on a labeled glass slide with a drop of clear mounting reagent.</li>
	</ol>
	</li>
	<li>Under a light microscope, randomly choose 20 views of non-overlapping cells from each coverslip for the cell extension assay.
	<ol>
		<li>Take photomicrographs at 400x magnification of each field of view. Directly count the number of each type of extension for each of the 20 representative cells. 
		NOTE: As such, 20 isolated cells should be examined for each tested condition to ensure reliable results. Filopodia were defined by cellular extensions with a base of 5 microns or less and a single apex. Lobopodia were defined by cellular extensions with a base of 5 to 20 microns of length containing extensions with multiple apices. Lamellipodia were defined by cell extensions that are greater than 20 microns in length and with or without apices. Depending on the tested cell type, the sizes of cell extensions may differ and may require refinement of identifying parameters.</li>
	</ol>
	</li>
	<li>Determine the average number of each cell extension in each cell type (i.e., SW-13, SW-Neo, SW-DDK) across the 6 wells examined.</li>
	<li>Using a one-way analysis of variance (ANOVA) statistical test, compare differences in the average percentage of cell-membrane extensions among the different test cell types.</li>
</ol>
2. Adhesion Assay
<ol>
	<li>Maintain SW-13, SW-Neo, and SW-DKK3 cells in a standard humidified incubator at 37.0 &#176;C and 5% CO2 in growth medium.
	<ol>
		<li>Using a hemocytometer, count and plate 100,000 cells of SW-13, SW-Neo, and SW-DKK3 per well into separate 6-well plates and grow overnight in growth medium.</li>
		<li>Seed 6-well plates for each cell type tested, using one plate for each of the 6 designated time points tested below. 
		NOTE: The time points may vary for different cell types.</li>
	</ol>
	</li>
	<li>After overnight incubation, wash cells with warm PBS once then add 0.5 mL of 1x non-enzymatic cell dissociation solution to each well.
	<ol>
		<li>Swirl the plate to spread the cell dissociation solution. Aspirate the designated plate at defined time points (i.e., 1, 2, 3, 5, 10, and 15 min) and then wash with 1 mL warm PBS solution three times.</li>
		<li>Between washes, gently tap the plates to detach loosely attached cells.</li>
	</ol>
	</li>
	<li>Aspirate any remaining PBS and fix the cells remaining attached to the plate with 1 mL of 3.7% formaldehyde for 10 min.</li>
	<li>Stain cells with 1 mL of 0.05% crystal violet for 30 min then wash excess dye away with 1 mL of deionized water. Titrate wash to promote cell visualization. 
	NOTE: Depending on the level of dye uptake, several additional washes may be needed to promote cell visualization.</li>
	<li>Using a light microscope at 100x magnification, count the remaining attached cells in each well for each plate. 
	NOTE: Use of transparent rulers or marking fine pen guides on the bottom side of the plate will help to avoid repeated counting of the same cells.</li>
	<li>Determine the average number of attached cells per well for each plate.</li>
	<li>Compare the rate of cell detachment between SW-13, SW-Neo, and SW-DDK3 cells over the given time period using a two-way ANOVA statistical test.</li>
</ol>

<ol>
	<li>Libe, R., Fratticci, A., Bertherat, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adrenocortical+cancer:+pathophysiology+and+clinical+management.">Adrenocortical cancer: pathophysiology and clinical management.</a> Endocrine-related cancer. 14 (1), 13-28 (2007).</li><li>Veeck, J., Dahl, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+the+Wnt+pathway+in+cancer:+the+emerging+role+of+Dickkopf-3.">Targeting the Wnt pathway in cancer: the emerging role of Dickkopf-3.</a> Biochimica et biophysica acta. 1825 (1), 18-28 (2012).</li><li>Friedl, P., Gilmour, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collective+cell+migration+in+morphogenesis,+regeneration+and+cancer.">Collective cell migration in morphogenesis, regeneration and cancer.</a> Nat Rev Mol Cell Biol. 10 (7), 445-457 (2009).</li><li>Jacquemet, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=L-type+calcium+channels+regulate+filopodia+stability+and+cancer+cell+invasion+downstream+of+integrin+signalling.">L-type calcium channels regulate filopodia stability and cancer cell invasion downstream of integrin signalling.</a> Nat Commun. 7, 13297 (2016).</li><li>Machesky, L. M., Li, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fascin:+Invasive+filopodia+promoting+metastasis.">Fascin: Invasive filopodia promoting metastasis.</a> Commun Integr Biol. 3 (3), 263-270 (2010).</li><li>Petrie, R. J., Harlin, H. M., Korsak, L. I., Yamada, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activating+the+nuclear+piston+mechanism+of+3D+migration+in+tumor+cells.">Activating the nuclear piston mechanism of 3D migration in tumor cells.</a> J Cell Biol. 216 (1), 93-100 (2017).</li><li>Korah, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epigenetic+silencing+of+RASSF1A+deregulates+cytoskeleton+and+promotes+malignant+behavior+of+adrenocortical+carcinoma.">Epigenetic silencing of RASSF1A deregulates cytoskeleton and promotes malignant behavior of adrenocortical carcinoma.</a> Molecular cancer. 12, 87 (2013).</li><li>Cheng, J. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+FOXO1-mediated+dedifferentiation+blocking+role+for+DKK3+in+adrenocortical+carcinogenesis.">A novel FOXO1-mediated dedifferentiation blocking role for DKK3 in adrenocortical carcinogenesis.</a> BMC cancer. 17 (1), 164 (2017).</li><li>Barry, D. J., Durkin, C. H., Abella, J. V., Way, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Open+source+software+for+quantification+of+cell+migration,+protrusions,+and+fluorescence+intensities.">Open source software for quantification of cell migration, protrusions, and fluorescence intensities.</a> J Cell Biol. 209 (1), 163-180 (2015).</li><li>Cliffe, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+3D+analysis+of+complex+single+border+cell+behaviors+in+coordinated+collective+cell+migration.">Quantitative 3D analysis of complex single border cell behaviors in coordinated collective cell migration.</a> Nat Commun. 8, 14905 (2017).</li></ol>

The authors have nothing to disclose.

Here we describe an in vitro quantitative method to characterize cell extensions with ease, few pit-falls, and reliable reproducibility that can be applied for various test conditions. Moreover, simple, quantifiable adhesion and/or motility assays can be performed simultaneously to correlate potential functional significance of observed alterations in cell membrane extensions.
However, these methods may present some potential limitations. First, the criteria specified here to identify...

Dysregulated WNT signaling plays a critical role in adrenocortical malignancies1. The methods used in this study investigate whether silencing of DKK3, a negative regulator of WNT signaling, represents a dedifferentiation event in the adrenal cortex and promotes tumor formation in the context of cell-extension repertoire changes. DKK3 is a 38 kDa secreted glycoprotein with an N-terminal signal peptide and previous studies have demonstrated that its enforced expression resulted in cell cycle arrest, inhibited aggressive malignant behavior, and reversed epithelial-mesenchymal transition2.
The malignant behavior of adrenocortical carcinoma (ACC) and other cancers is, in part, influenced by the ability of tumor cells to interface with the surrounding surfaces, including the extracellular matrix, which in turn facilitates tumor cell invasion and migration3. The role of specific cell membrane extensions in cancer progression is being increasingly demonstrated in various contexts, primarily via the formation of filopodia. For example, overexpression of L-type calcium channels has been found to induce filopodia formation and promote tumor cell invasion4. Similarly, Fascin, an actin binding protein minimally expressed in normal tissue, is also overexpressed in cancer cells in association with filopodia formation5. Lobopodia formation enables non-malignant fibroblasts to migrate effectively through the extra-cellular matrix, however, it has been shown that fibrosarcoma cells rely on metalloproteinase activity in lieu of lobopodia to facilitate cell migration and invasion6. We have shown that tumor suppressors, including Ras association domain family 1 isoform A (RASSF1A) and DKK3, can function to alter cytoskeletal elements and promote lamellipodia formation and stymie invasive properties7,8.
As such, it is critical to characterize the effects of genes involved in carcinogenesis and their relationship to cell-membrane extension alterations, specifically assessing filopodia, lobopodia, and lamellipodia formation under test conditions. Current state-of-the art techniques include the use of increasingly sophisticated microscopy methods, fluorescent labeling, and/or complex computer algorithms for data acquisition and interpretation. While these methods provide new and powerful analytic tools, their complexity limits their widespread use and adaptability in cell biology experiments. Furthermore, the precise quantification and observation of changes in cell extension morphology is not typically measured9,10. In contrast, we introduce a technique here that accurately quantifies cell extension alterations using standard microscopic techniques and readily adaptable in vitro methods. These methods also quantify each cell extension type simultaneously for each cell analyzed and determine overall changes in the cell membrane extension repertoire. We also show how these changes can relate to cell adhesion properties.
As an experimental example, we will use a previously created cell line of SW-13, designated SW-DDK3, which has been stably transfected with pCMV6-Entry/DKK3 plasmid vectors and constitutively overexpresses DKK3, a differentiating factor in the adrenal gland. Non-transfected SW-13 cells and SW-13 cells stably transfected with empty vector (pCMV6-Entry), designated SW-Neo, will serve as experimental controls.

<table width="653">
	<tbody>
		<tr height="63">
			<td height="63" style="width:216px;height:63px;">Dulbecco&#39;s Modified Eagle Medium (DMEM)</td>
			<td style="width:115px;">ThermoFisher</td>
			<td style="width:119px;">11965-092</td>
			<td style="width:203px;">Supplemented with fetal bovine serum and penicllin and streptomycin</td>
		</tr>
		<tr height="42">
			<td height="42" style="width:216px;height:42px;">Deulbeco&#39;s Phosphate Buffered Saline</td>
			<td style="width:115px;">Sigma-Aldrich</td>
			<td style="width:119px;">D8537</td>
			<td>1X solution, used directly</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:216px;height:21px;">3.7% formaldehyde&#160;</td>
			<td style="width:115px;">Sigma-Aldrich</td>
			<td style="width:119px;">F8775</td>
			<td>Dilute stock solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:216px;height:21px;">0.05% crystal violet&#160;</td>
			<td style="width:115px;">Harleco</td>
			<td style="width:119px;">192-12</td>
			<td>Dilute stock solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:216px;height:21px;">De-ionized water</td>
			<td style="width:115px;">NA</td>
			<td style="width:119px;">NA</td>
			<td>NA</td>
		</tr>
		<tr height="42">
			<td height="42" style="width:216px;height:42px;">Microscope with 400X magnification&#160;</td>
			<td style="width:115px;">NA</td>
			<td style="width:119px;">NA</td>
			<td>NA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6-well plates</td>
			<td>Corning</td>
			<td>353046</td>
			<td>NA</td>
		</tr>
		<tr height="43">
			<td height="43" style="width:216px;height:43px;">Cell dissociation solution non-enzymatic 1X</td>
			<td style="width:115px;">Sigma-Aldrich</td>
			<td style="width:119px;">C5914&#160;</td>
			<td>1X solution, used directly</td>
		</tr>
	</tbody>
</table>

characterization of cell membrane extensions and studying their roles in cancer cell adhesion dynamics

The cell membrane&#39;s extension repertoire modulates various malignant behaviors of cancer cells, including their adhesive and migratory potentials. The ability to accurately classify and quantify cell extensions and measure the effect on a cell&#39;s adhesive capacity is critical to determining how cell-signaling events impact cancer cell behavior and aggressiveness. Here, we describe the in vitro design and use of a cell extension quantification method in conjunction with an adhesion capacity assay in an established in vitro model for adrenocortical carcinoma (ACC). Specifically, we test the effects of DKK3, a putative tumor suppressor and a pro-differentiation factor, on the membrane extension phenotype of the ACC cell line, SW-13. We propose these assays to provide relatively simple, reliable, and easily interpretable metrics to measures these characteristics under various experimental conditions.

Using the above assays, the effects of DKK3 overexpression on cell extension morphology and cell adhesion properties were tested in the established ACC cell line SW-13, in vitro. Cells overexpressing DKK3 were generated by stably transfecting SW-13 cells with Myc-DDK tagged pCMV6-Entry/DKK3 plasmid vectors and designated as SW-DKK3. Similarly, cells stably transfected with empty vector pCMV6-Entry were created as a transfection and passaging control and defined as SW-Neo. SW-13 c...

Watch this Scientific Journal Video about Characterization of Cell Membrane Extensions and Studying Their Roles in Cancer Cell Adhesion Dynamics at JoVE.com

Characterization of Cell Membrane Extensions and Studying Their Roles in Cancer Cell Adhesion Dynamics

This study demonstrates the utility and ease of quantitative cell membrane extension measurement and its correlation to adhesive capacity of cells. As a representative example, we show here that Dickkopf-related protein 3 (DKK3) promotes increased lobopodia formation and cell adhesiveness in adrenocortical carcinoma cells in vitro.

The cell membrane&#39;s extension repertoire modulates various malignant behaviors of cancer cells, including their adhesive and migratory potentials. The ...

characterization-cell-membrane-extensions-studying-their-roles-cancer

Research

JoVE Journal

Cancer Research

7.4K Views.  Yale University School of Medicine. This study demonstrates the utility and ease of quantitative cell membrane extension measurement and its correlation to adhesive capacity of cells. As a representative example, we show here that Dickkopf-related protein 3 (DKK3) promotes increased lobopodia formation and cell adhesiveness in adrenocortical carcinoma cells in vitro.

Video: Characterization of Cell Membrane Extensions and Studying Their Roles in Cancer Cell Adhesion Dynamics

A Protocol for Rapid Post-mortem Cell Culture of Diffuse Intrinsic Pontine Glioma (DIPG)

Diffuse Intrinsic Pontine Glioma (DIPG) is a childhood brainstem tumor that carries a universally fatal prognosis. Because surgical resection is not a viable treatment strategy and biopsy is not routinely performed, the availability of patient samples for research is limited. Consequently, efforts to study this disease have been challenged by a paucity of faithful disease models. To address this need, we describe here a protocol for the rapid processing of post-mortem autopsy tissue samples in order to generate durable patient-derived cell culture models that can be used in in vitro assays or in vivo orthotopic xenograft experiments. These models can be used to screen for potential drug targets and to study fundamental pathobiological processes within DIPG. This protocol can further be extended to analyze and isolate tumor and microenvironmental cells using Fluorescence-activated Cell Sorting (FACS), which enables subsequent analysis of gene expression, protein expression, or epigenetic modifications of DNA at the bulk cell or single cell level. Finally, this protocol can also be adapted to generate patient-derived cultures for other central nervous system tumors.

A Protocol for Rapid Post-mortem Cell Culture of Diffuse Intrinsic Pontine Glioma DIPG

This protocol describes a method for the rapid processing of post-mortem diffuse intrinsic pontine glioma samples for the establishment of patient-derived cell culture models or direct characterization of tumor and microenvironmental cells.

Diffuse Intrinsic Pontine Glioma (DIPG) is a childhood brainstem tumor that carries a universally fatal prognosis. Because surgical resection is not a ...

Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro

Depletion of the mitochondrial membrane potential (MMP, &#916;&#936;m) is considered the earliest event in the apoptotic cascade. It even occurs ahead of nuclear apoptotic characteristics, including chromatin condensation and DNA breakage. Once the MMP collapses, cell apoptosis will initiate irreversibly. A series of lipophilic cationic dyes can pass through the cell membrane and aggregate inside the matrix of mitochondrion, and serve as fluorescence marker to evaluate MMP change. As one of the six members of the Cl- intracellular channel (CLIC) family, CLIC4 participates in the cell apoptotic process mainly through the mitochondrial pathway. Here we describe a detailed protocol to measure MMP via monitoring the fluorescence fluctuation of Rhodamine 123 (Rh123), through which we study apoptosis induced by CLIC4 knockdown. We discuss the advantages and limitations of the application of confocal laser scanning and normal fluorescence microscope in detail, and also compare it with other methods.

Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro

Here we present a detailed protocol for the application of rhodamine 123 to identify the mitochondrial membrane potential (MMP) and study CLIC4 knockdown-induced HN4 cell apoptosis in vitro. Under common fluorescence microscope and confocal laser scanning fluorescence microscope, the real-time change of the MMP was recorded.

Depletion of the mitochondrial membrane potential (MMP, &#916;&#936;m) is considered the earliest event in the apoptotic cascade. It even occurs ahead of ...

Target Cell Pre-enrichment and Whole Genome Amplification for Single Cell Downstream Characterization

Rare target cells can be isolated from a high background of non-target cells using antibodies specific for surface proteins of target cells. A recently developed method uses a medical wire functionalized with anti-epithelial cell adhesion molecule (EpCAM) antibodies for in vivo isolation of circulating tumor cells (CTCs)1. A patient-matched cohort in non-metastatic prostate cancer showed that the in vivo isolation technique resulted in a higher percentage of patients positive for CTCs as well as higher CTC counts as compared to the current gold standard in CTC enumeration. As cells cannot be recovered from current medical devices, a new functionalized wire (referred to as Device) was manufactured allowing capture and subsequent detachment of cells by enzymatic treatment. Cells are allowed to attach to the Device, visualized on a microscope and detached using enzymatic treatment. Recovered cells are cytocentrifuged onto membrane-coated slides and harvested individually by means of laser microdissection or micromanipulation. Single-cell samples are then subjected to single-cell whole genome amplification allowing multiple downstream analysis including screening and target-specific approaches. The procedure of isolation and recovery yields high quality DNA from single cells and does not impair subsequent whole genome amplification (WGA). A single cell&#39;s amplified DNA can be forwarded to screening and/or targeted analysis such as array comparative genome hybridization (array-CGH) or sequencing. The device allows ex vivo isolation from artificial rare cell samples (i.e. 500 target cells spiked into 5 mL of peripheral blood). Whereas detachment rates of cells are acceptable (50 - 90%), the recovery rate of detached cells onto slides spans a wide range dependent on the cell line used (&#60;10 - &#62;50%) and needs some further attention. This device is not cleared for the use in patients.

This protocol is to recover and prepare rare target cells from a mixture with non-target background cells for molecular genetic characterization at the single-cell level. DNA quality is equal to non-treated single cells and allows for single-cell application (both screening based and targeted analysis).

Rare target cells can be isolated from a high background of non-target cells using antibodies specific for surface proteins of target cells. A recently ...

3-D Cell Culture System for Studying Invasion and Evaluating Therapeutics in Bladder Cancer

Bladder cancer is a significant health problem. It is estimated that more than 16,000 people will die this year in the United States from bladder cancer. While 75% of bladder cancers are non-invasive and unlikely to metastasize, about 25% progress to an invasive growth pattern. Up to half of the patients with invasive cancers will develop lethal metastatic relapse. Thus, understanding the mechanism of invasive progression in bladder cancer is crucial to predict patient outcomes and prevent lethal metastases. In this article, we present a three-dimensional cancer invasion model which allows incorporation of tumor cells and stromal components to mimic in vivo conditions occurring in the bladder tumor microenvironment. This model provides the opportunity to observe the invasive process in real time using time-lapse imaging, interrogate the molecular pathways involved using confocal immunofluorescent imaging and screen compounds with the potential to block invasion. While this protocol focuses on bladder cancer, it is likely that similar methods could be used to examine invasion and motility in other tumor types as well.

The processes governing bladder cancer invasion represent opportunities for biomarker and therapeutic development. Here we present a bladder cancer invasion model which incorporates 3-D culture of tumor spheroids, time-lapse imaging and confocal microscopy. This technique is useful for defining the features of the invasive process and for screening therapeutic agents.

Bladder cancer is a significant health problem. It is estimated that more than 16,000 people will die this year in the United States from bladder cancer. ...

Mesenchymal Stem Cell Isolation from Pulp Tissue and Co-Culture with Cancer Cells to Study Their Interactions

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor environment and cell-cell interactions. Identification of cancer and stem cell interactions, including changes in extracellular environment, physical interactions, and secreted factors, might enable the discovery of new therapy options. We combine known co-culture techniques to create a model system for mesenchymal stem cells (MSCs) and cancer cell interactions. In the current study, dental pulp stem cells (DPSCs) and PC-3 prostate cancer cell interactions were examined by direct and indirect co-culture techniques. Condition medium (CM) obtained from DPSCs and 0.4 &#181;m pore sized trans-well membranes were used to study paracrine activity. Co-culture of different cell types together was performed to study direct cell-cell interaction. The results revealed that CM increased cell proliferation and decreased apoptosis in prostate cancer cell cultures. Both CM and trans-well system increased cell migration capacity of PC-3 cells. Cells stained with different membrane dyes were seeded into the same culture vessels, and DPSCs participated in a self-organized structure with PC-3 cells under this direct co-culture condition. Overall, the results indicated that co-culture techniques could be useful for cancer and MSC interactions as a model system.

We provide protocols for evaluation of mesenchymal stem cells isolated from dental pulp and prostate cancer cell interactions based on direct and indirect co-culture methods. Condition medium and trans-well membranes are suitable to analyze indirect paracrine activity. Seeding differentially stained cells together is an appropriate model for direct cell-cell interaction.

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor ...

Establishment of Gastric Cancer Patient-derived Xenograft Models and Primary Cell Lines

The use of preclinical models to advance our understanding of tumor biology and investigate the efficacy of therapeutic agents is key to cancer research. Although there are many established gastric cancer cell lines and many conventional transgenic mouse models for preclinical research, the disadvantages of these in vitro and in vivo models limit their applications. Because the characteristics of these models have changed in culture, they no longer model tumor heterogeneity, and their responses have not been able to predict responses in humans. Thus, alternative models that better represent tumor heterogeneity are being developed. Patient-derived xenograft (PDX) models preserve the histologic appearance of cancer cells, retain intratumoral heterogeneity, and better reflect the relevant human components of the tumor microenvironment. However, it usually takes 4-8 months to develop a PDX model, which is longer than the expected survival of many gastric patients. For this reason, establishing primary cancer cell lines may be an effective complementary method for drug response studies. The current protocol describes methods to establish PDX models and primary cancer cell lines from surgical gastric cancer samples. These methods provide a useful tool for drug development and cancer biology research.

The current protocol describes methods to establish patient-derived xenograft (PDX) models and primary cancer cell lines from surgical gastric cancer samples. The methods provide a useful tool for drug development and cancer biology research.

The use of preclinical models to advance our understanding of tumor biology and investigate the efficacy of therapeutic agents is key to cancer research. ...

Semi-automatic PD-L1 Characterization and Enumeration of Circulating Tumor Cells from Non-small Cell Lung Cancer Patients by Immunofluorescence

Circulating tumor cells (CTCs) derived from the primary tumor are shed into the bloodstream or lymphatic system. These rare cells (1&#8722;10 cells per mL of blood) warrant a poor prognosis and are correlated with shorter overall survival in several cancers (e.g., breast, prostate and colorectal). Currently, the anti-EpCAM-coated magnetic bead-based CTC capturing system is the gold standard test approved by the U.S. Food and Drug Administration (FDA) for enumerating CTCs in the bloodstream. This test is based on the use of magnetic beads coated with anti-EpCAM markers, which specifically target epithelial cancer cells. Many studies have illustrated that EpCAM is not the optimal marker for CTC detection. Indeed, CTCs are a heterogeneous subpopulation of cancer cells and are able to undergo an epithelial-to-mesenchymal transition (EMT) associated with metastatic proliferation and invasion. These CTCs are able to reduce the expression of cell surface epithelial marker EpCAM, while increasing mesenchymal markers such as vimentin. To address this technical hurdle, other isolation methods based on physical properties of CTCs have been developed. Microfluidic technologies enable a label-free approach to CTC enrichment from whole blood samples. The spiral microfluidic technology uses the inertial and Dean drag forces with continuous flow in curved channels generated within a spiral microfluidic chip. The cells are separated based on the differences in size and plasticity between normal blood cells and tumoral cells. This protocol details the different steps to characterize the programmed death-ligand 1 (PD-L1) expression of CTCs, combining a spiral microfluidic device with customizable immunofluorescence (IF) marker set.

The characterization of circulating tumor cells (CTCs) is a popular topic in translational research. This protocol describes a semi-automatic immunofluorescence (IF) assay for PD-L1 characterization and enumeration of CTCs in non-small cell lung cancer (NSCLC) patient samples.

Circulating tumor cells (CTCs) derived from the primary tumor are shed into the bloodstream or lymphatic system. These rare cells (1&#8722;10 cells per mL ...

Radiosensitivity of Cancer Stem Cells in Lung Cancer Cell Lines

The presence of cancer stem cells (CSCs) has been associated with relapse or poor outcomes after radiotherapy. Studying radioresistant CSCs may provide clues to overcoming radioresistance. Voltage-gated calcium channel &#945;2&#948;1 subunit isoform 5 has been reported as a marker for radioresistant CSCs in non-small cell lung cancer (NSCLC) cell lines. Using calcium channel &#945;2&#948;1 subunit as an example of a CSC marker, methods to study the radiosensitivity of CSCs in NSCLC cell lines are presented. CSCs are sorted with putative markers by flow cytometry, and the self-renewal capacity of sorted cells is evaluated by sphere formation assay. Colony formation assay, which determines how many cells lose the ability to generate descendants forming the colony after a certain dose of radiation, is then performed to assess the radiosensitivity of sorted cells. This manuscript provides initial steps for studying the radiosensitivity of CSCs, which establishes the basis for further understanding of the underlying mechanisms.

The presence of cancer stem cells have been associated with relapse or poor outcomes after radiotherapy. This manuscript describes the methods to study the radiosensitivity of cancer stem cells in lung cancer cell lines.

The presence of cancer stem cells (CSCs) has been associated with relapse or poor outcomes after radiotherapy. Studying radioresistant CSCs may provide ...

Comparing Metastatic Clear Cell Renal Cell Carcinoma Model Established in Mouse Kidney and on Chicken Chorioallantoic Membrane

Metastatic clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. Localized ccRCC has a favorable surgical outcome. However, one third of ccRCC patients will develop metastases to the lung, which is related to a very poor outcome for patients. Unfortunately, no therapy is available for this deadly stage, because the molecular mechanism of metastasis remains unknown. It has been known for 25 years that the loss of function of the von Hippel-Lindau (VHL) tumor suppressor gene is pathognomonic of ccRCC. However, no clinically relevant transgenic mouse model of ccRCC has been generated. The purpose of this protocol is to introduce and compare two newly established animal models for metastatic ccRCC. The first is renal implantation in the mouse model. In our laboratory, the CRISPR gene editing system was utilized to knock out the VHL gene in several RCC cell lines. Orthotopic implantation of heterogeneous ccRCC populations to the renal capsule created novel ccRCC models that develop robust lung metastases in immunocompetent mice. The second model is the chicken chorioallantoic membrane (CAM) system. In comparison to the mouse model, this model is more time, labor, and cost-efficient. This model also supported robust tumor formation and intravasation. Due to the short 10 day period of tumor growth in CAM, no overt metastasis was observed by immunohistochemistry (IHC) in the collected embryo tissues. However, when tumor growth was extended by two weeks in the hatched chicken, micrometastatic ccRCC lesions were observed by IHC in the lungs. These two novel preclinical models will be useful to further study the molecular mechanism behind metastasis, as well as to establish new, patient-derived xenografts (PDXs) toward the development of novel treatments for metastatic ccRCC.

Metastatic clear cell renal cell carcinoma is a disease without a comprehensive animal model for thorough preclinical investigation. This protocol illustrates two novel animal models for the disease: the orthotopically implanted mouse model and the chicken chorioallantoic membrane model, both of which demonstrate lung metastasis resembling clinical cases.

Metastatic clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. Localized ccRCC has a favorable surgical outcome. However, ...

Quantification of Tumor Cell Adhesion in Lymph Node Cryosections

Tumor-draining lymph nodes (LNs) are not merely filters of tumor-produced waste. They are one of the most common regional sites of provisional residence of disseminated tumor cells in patients with different types of cancer. The detection of these LN-residing tumor cells is an important biomarker associated with poor prognosis and adjuvant therapy decisions. Recent mouse models have indicated that LN-residing tumor cells could be a substantial source of malignant cells for distant metastases. The ability to quantify the adhesivity of tumor cells to LN parenchyma is a critical gauge in experimental research that focuses on the identification of genes or signaling pathways relevant for lymphatic/metastatic dissemination. Because LNs are complex 3D structures with a variety of appearances and compositions in tissue sections depending on the plane of section, their matrices are difficult to replicate experimentally in vitro in a fully controlled way. Here, we describe a simple and inexpensive method that allows the quantification of adhesive tumor cells to LN cryosections. Using serial sections of the same LN, we adapt the classic method developed by Brodt to use nonradioactive labels and directly count the number of adhering tumor cells per LN surface area. LN-adherent tumor cells are readily identified by light microscopy and confirmed by a fluorescence-based method, giving an adhesion index that reveals the cell-binding affinity to LN parenchyma, which is suggestive evidence of molecular alterations in the affinity binding of integrins to their correlate LN-ligands.

Here, we describe a simple and inexpensive method that allows the quantification of adhesive tumor cells to lymph node (LN) cryosections. LN-adherent tumor cells are readily identified by light microscopy and confirmed by a fluorescence-based method, giving an adhesion index that reveals the tumor cell-binding affinity to LN parenchyma.

Tumor-draining lymph nodes (LNs) are not merely filters of tumor-produced waste. They are one of the most common regional sites of provisional residence ...